


Strings of Fate

by arcadenemesis



Series: As Prophecised [1]
Category: Voltron: Legendary Defender
Genre: Alternate Universe - Warlocks, Blood Pacts, Blood and Injury, Demon Shiro (Voltron), Enemies to Lovers, First Meetings, Keith's Father (Voltron) Lives, Kiss of Life, M/M, Mind Control, Prophecies, Supernatural Elements, Urban Fantasy, Violinist Keith (Voltron)
Language: English
Status: Completed
Published: 2020-09-27
Updated: 2020-09-27
Packaged: 2021-03-07 18:35:59
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,625
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26662303
Author URL: https://archiveofourown.org/users/arcadenemesis/pseuds/arcadenemesis
Summary: "Demon!" someone cries.The creature is huge, towering well over ten feet tall, discounting the curling horns that crown his head. It lets out a guttural roar and turns lilac, unseeing eyes onto them. Invisible chains tether it to the will of a master. Keith freezes. Whoever controls it must be frighteningly powerful; demons, for all their pacts and deals, are creatures of autonomy. This one is merely a puppet of someone's design. Terrifying… Beautiful.With the power to defy death, Keith and his violin become the fulcrum of a supernatural war he never asked for. Haggar will send her best warriors and champions to retrieve him in the hope of bringing back the one she loves.
Relationships: Keith/Shiro (Voltron)
Series: As Prophecised [1]
Series URL: https://archiveofourown.org/series/1941031
Comments: 13
Kudos: 112
Collections: Bad Boys





	Strings of Fate

**Author's Note:**

  * For [st00pz](https://archiveofourown.org/users/st00pz/gifts).



A solitary note rings out, cutting through the eerie midnight fog. For a moment, their battlefield falls silent, as if all living creatures turn to listen to the spell. Keith knows he possesses an instrument of paradoxes. It cradles his face so tenderly where it presses to his chin, and cuts deep enough to draw blood on his longest songs where fingertips meet strings. It sings so sweetly to an audience of men and monsters, then strikes into enemies like a parasite. Energy crackles and fizzles around him, a siren call of its own. This power, it's Keith's alone. He won't let them have it. 

Over the ceaseless motion of his bow, he locks eyes with the beast that confronts him, watching as his tune takes hold. Its pursuit stops still, and the eldritch glow of purple recedes to something almost…human. Keith closes his eyes as he continues to play. 

Such a delicate thing, his violin. 

Such violence it brings.

* * *

"Keith, enough messing around with your food. Eat."

He isn't petulant enough to sigh, but he does pause to bring the contents of his spoon to eye-level. He  _ is _ grateful, he reminds himself. He may be living his life underground, hiding from a war beyond these walls, but there are worse things. He could be alone. 

"Sorry, pop," he murmurs. "It's just…hard to pretend everything's normal. Not when everything is about to change." A hand ruffles through his hair, and finally he glances up to look into his father's kind eyes. 

"You were always going to turn twenty-one one day, son," he says, southern drawl a salve. Keith often wonders if there's a little magic in him too when he sets him at ease so effortlessly. "Just came around a bit quicker than we expected."

Keith huffs a laugh, but he drops the spoon back in his bowl, failing to find his appetite.

"Your ma's the best sorceress I know. If anyone will come up with something, it's her."

It's true, Keith knows. But even his mother has her limits. A prophecy hangs heavy over their heads, of a boy born of Marmoran blood that will be the key to unlocking the secrets of death itself. That gift is coveted. For centuries before his birth, the witch Haggar has been seeking it to revive her lover and bring back his dormant empire in all its bloody glory. It is only his mother's magic that has kept him away from Haggar's eye all these years. But she's looking for him, and the war she wages in pursuit grows ever-near. The clock is ticking and the slow metronome is maddening.

Keith is ready to finally embrace the strike of midnight.

* * *

Instruments pepper the studio he calls home. A panpipe on the kitchen table, a guitar on the fading couch, a cello on the floor—Keith knows how to play them all. He plucks absently at a string on a lyre and feels the magic around him hum its response. All his life, it has been a cacophony that follows him everywhere. 

It's curious that music would be the machina that brings him silence, allow his mind to settle and let him take command of that ever-present, endless power. For most of his Clan, blades are the preferred conduit of their magic, over runes written by quills or incantations recited by memory. That's not to say a blade doesn't feel good in his hands—there's just something about shaping spells with sound that he can't resist.

Still, it feels like an imperfect fit. The energy within feels bigger than his body can contain, and even the melodies he weaves only seem to stave off his inevitable destruction temporarily. It's a matter of finding the right vessel, one that will let him harness the power that swirls around him. But every time he speaks such words aloud, his mother simply frowns and his father looks away uncomfortably. They're scared—of the magic's effect or just him, Keith doesn't quite know. He's sick of being scared too.

Downstairs, Keith hears a door softly click shut and the sound of hushed voices. He creeps to the top of the spiral staircase, watching as his mother walks through the apartment. His father follows close behind, tenderly peeling away the leather jacket from her shoulders. She looks furious. 

"What is so foolish about wanting to protect my only child?" she hisses. "Kolivan can't hope to understand. Haggar will do  _ anything _ to get to him. I would die to prevent that from happening."

"I know, doll," his father murmurs. "And for his entire life, you've done just that. But maybe it's time we—"

"I don't want to hear the maybes," she says, rounding on him. "It's not about stopping Haggar or even Zarkon. Keith deserves an ordinary life."

"Krolia," his father intones, still so softly. "Is this really an ordinary life we're giving him right now?"

The static of silence that follows drowns out the hum of magic that lingers around him. Keith swallows down the lump in his throat.

"I want to fight."

Two pairs of eyes whip up to him, surprised and guilty. 

"I don't care about ordinary," he says, sure and firm. "But I want this to be over—for all of us."

"Keith…" his mother begins, but he won't let her finish.

"If I'm the one Haggar wants, if I'm the reason this war with our family is raging on, I don't want to ignore it. I want to face it head on."

Keith sees the moment the fight leaves her, senses the way the magic within her softens into resignation. 

"Come down. There is something I need to give you."

Instead of taking the steps one-by-one, Keith vaults the railings. A rush of wind cushions his landing as his mother sighs in disapproval, but she doesn't waste words on scolding him.

"Follow me," she says, leading the way to the study. With a flick of her fingers, the bookcase on the far wall warps and vanishes, revealing the room hidden beyond. 

"Pop's armoury?" Keith frowns, glancing to the man over his shoulder. There's an amused gleam in his eye as he smiles back to him.

"Not every weapon in here is…traditional."

Keith opens his mouth to question, but his mother speaks first.

"Keith…" 

He turns to find her staring down at the so-named "weapon" in her hands. 

"This violin has been passed down in our family for centuries, carved out of Wyrmwood by the progenitor of our bloodline. In the hands of the right person, it is a tool of creation and destruction."

It looks so unassuming in her hands. It's beautiful, carefully crafted no doubt, but powerful? Destructive? Hardly. To the eye, it's just wood and string married neatly together, save for the strange symbols carved in place of the f-holes. There's a reluctant pause before his mother holds both violin and bow out to him.

"Take it."

Keith hesitates. It seems like a test. 

"Take it, son," his father assures at his back. "See how it sounds."

He still feels uncertain, but he obeys, taking the instrument for himself and tucking the rest under his chin. With a nod from his father, he presses his fingers into the strings at its neck and brings the bow up ready. Keith has no idea when it was last tuned, but when he draws the bow over the E-string, it produces a perfect sound. Keith hardly hears it. 

For him, in that moment, everything suddenly snaps into place. The magic swirling around him stops and bends obediently to his will, awaiting instruction. The energy inside him swells, but flows instead of floods. It feels like a sudden epiphany, a moment of understanding, and when it settles, he sees the resignation in his mother's face. 

"Haggar was right. You are the one foretold."

* * *

The minutes before midnight seem far better suited for a funeral than a birthday. But Keith supposes that can only be expected in war. Tonight, they make their stand in a long-abandoned ghost town, far away from the rest of civilisation amongst rubble, overgrown streets and burnt-out cars. The Marmora Clan is out in force, some strolling the empty streets with a vigilant eye, others cleaning their Blades or testing their spells as they wait. The chance that they'll all survive this night is slim, and it hangs heavy in the air.

They tell him he has the power to fight Death itself... How ironic that so many lives have already ended—will continue to end—in the fight to have him.

The Clan Leader has only one directive for Keith: assist only where possible, but above all, stay hidden. It's ridiculous; Keith is easily the strongest mage in the field. To reduce his role to a glorified game of hide and seek is just poor strategy in his opinion. Only a look from his mother makes him hold his tongue. 

"Stay on your guard," Kolivan tells the others gruffly. "It won't take long for them to find us when the spell breaks. Haggar will send her closest soldiers. We will need to put them down before they can relay any intel back to her."

In the midst of the preparations, his father leans down to speak quietly in his ear as he adjusts his gauntlets. "Reckon they'll be up for birthday beers after this?"

"I might need something harder," Keith mutters back, but it cracks the tension for a moment and they both try not to laugh as Kolivan raises a brow in their direction.

Seconds tick down in silence until his father's watch beeps once to indicate midnight. 

"Happy 21st, kiddo," he says, as his mother kisses his head on his other side and ushers him into the shadows. 

It's instantaneous. The warmth of his mother's protection spell evaporates and Keith feels goosebumps skitter over his skin. Then a distant rumble, like thunder, draws near. 

"Sendak," Kolivan says knowingly. 

It begins. 

Haggar's most infamous General arrives through a portal of shadows and crackling electricity, taking vantage on an overturned pick-up as his army surges through behind him. It isn't all he brings with him though, heavy footsteps shaking the earth beneath them.

"Demon!" someone cries.

The creature is huge, towering well over ten feet tall, discounting the curling horns that crown his head. It lets out a guttural roar and turns lilac, unseeing eyes onto them. Invisible chains tether it to the will of a master. Keith freezes. Whoever controls it must be frighteningly powerful; demons, for all their pacts and deals, are creatures of autonomy. This one is merely a puppet of someone's design. Terrifying… Beautiful. 

Side by side with the General, they are an odd match. On his left, Sendak's arm hovers separate from his shoulder, an artificial design of metal with an odd energy signature. The demon's right arm is similarly severed from its body, phantom-like in the way it floats like smoke beside him.

_ What kind of witchcraft could dismember a living demon? _

The cries of his Marmoran brethren bring Keith back to his senses. Blades materialise in their hands as they meet the charge in a clash of sparks and smoke. But he can't let himself become lost to the violence surrounding him. In the shadows of a smashed storefront, he tucks his violin under his chin and raises his bow, taking a deep breath.

The trill rises above the sounds of clashes and blasts to settle over the battle, amplifying the magic of his allies and dampen his foes. It draws attention to him in an instant.

"The song-caster!" Sendak bellows, looking around wildly for the source. "Bring him to me!"

There's scuffling close by immediately and Keith rolls his eyes. So much for hiding. One of Sendak's grunts emerges from the dust and shrieks in surprise as they lays eyes on Keith. The soldier is bold enough to lunge immediately, without taking the time to size their opponent up. Huffing his annoyance, Keith halts his song to twirl the bow in his fingers, feeling it grow and transform in his hands. With a slash, the enemy goes down with a spray of blood, caught unaware by the blade suddenly in Keith's grip. 

To his left, he hears a crunch of bone and a wail, and he whirls around to see his father taking down another mindless soldier. Without magic of his own, his father relies purely on the strength of his fists. Still, he goes toe-to-toe with the swarm, and Keith isn't sure he'd label him at a disadvantage. He's already grimy from battle, but he's coming out on top, flashing him a grin.

"Watch your back, son."

The words are like a spell of their own. Suddenly, his father jolts before him, eyes going wide. Keith looks down to see the bloom of blood where metal claws have hooked into his father's side, and suddenly the battlefield slows down around them. Maybe he's just frozen still, because before he can say a word, the claws wrench and toss the body in its grip like a ragdoll. 

But his father never lands. The air around him crackles with black magic, and then it's as if the sky swallows him up, leaving nothing behind.

"No!!"

He's gone, just like that, all because he simply stood in the way. Keith watches the clawed hand shoot back to Sendak's side, fury and grief a potion bubbling in his chest. There's nothing to be gained from laying low in this fight. Glass and gravel crunch under his boots as he steps out into  the street under the dim light of the crescent moon, the blade in his hand shrinking back down to its original form. His eyes sting with heat as he brings his bow back to the violin, and it begins to pulse a luminescent white as he plays with murderous intent. His Clan holds back warily as he strikes the strings with frenzy until his fingers ache, soldiers around him falling down still as death without so much as touching them or even sparing them a glance. He doesn't want to simply bring Haggar's pawns to a halt. For hurting his family, he will  _ destroy _ them.

"Seize him, Shiro," Sendak commands the demon by his side.

Lifeless eyes lock onto Keith, and he tucks the bow to his wrist as the demon's own severed arm rushes toward him. With deft fingers, he plucks the strings, the short, sharp sound meeting the hand in a clash of magic, deflecting it away. The demon hesitates as if caught off-guard, and Keith frowns. Curiously, the lilac glow of his eyes shutters for just a moment, revealing a kinder grey beneath. Startled and afraid, Keith thinks this may be his true face that he sees. 

"I said,  _ seize him _ !"

At the words, the unnatural light returns, expression closing off, and the beast growls, lumbering forward. Keith hears his mother's voice, but he doesn't move, blood rushing in his ears. That flash of grey is seared into his mind. The magic holding the demon— _ Shiro _ —against his will is strong…

But maybe Keith is stronger. 

A solitary note, that's how it starts. A long, mournful sound that washes over the battlefield as the beast draws near. Keith closes his eyes, leaving his heart open and vulnerable as he pours himself into a tender song of arpeggios, lilting and sweet. It's a plea, a gentle imploration for the will of the being within to break free.

Keith opens his eyes again when the footsteps cease, locking his gaze with empty eyes. The demon hunches, bringing their faces barely inches apart…

And whines quietly, in key with the sound of the violin's song.

It's all been a gamble so far, so Keith rolls the dice one more time. He lowers his violin and bow in one hand, bringing the other to the cheek of the demon.

"I know you're in there," Keith says softly, searching. "Shiro…"

The demon blinks once, twice, and the glow recedes to the same warm grey as before. He takes a sharp breath, as if stunned. 

"You…" Shiro whispers, hoarse, as if he hasn't heard his own voice in years. He doesn't have a chance to finish his sentence.

"Kill them!" Sendak bellows, furious. "Kill them all!"

Wide eyed innocence makes Keith wonder if the demon has heard at all. But then rage fills the face before him. Keith knows it isn't for him. 

"Play," Shiro implores, in a way that makes heat spread through him. "We can finish this."

Keith can't explain why, but he feels this moment is kismet between them, as if their meeting was an unwritten part of his prophecy. With a minute nod, he brings the violin back under his chin and feels Shiro's energy ignite as he plays the first note. The demon grins, a wild little thing that makes Keith's heart rate spike, and he spins to meet their startled foes with a sweep of his detached arm, sending them all flying. The Marmorans seem unsure of what to do, but thankfully they take the development in stride, giving them both a wide berth on the battlefield. Imbued with the overwhelming power of Keith's song, they cut through Sendak's men without rest. It makes the pain in his fingers, pressed raw into the strings, a distant thought. 

Setting his eyes on Sendak, Keith takes a step forward.

"Where did you send my father?" he demands, punctuating the question with a ricochet of his bow that fells the enemies that lunge at him with a visible concentric wave of sound.

Sendak only snarls.

"Bring him back and I'll spare your men!"

It's a bloodbath at this point. The Marmorans have taken casualties, but they pale to the fodder of the army around them. Still, their enemy fights, seemingly blind in its attack. Keith turns too late to the sound of rushing footsteps lost under his music, but as he comes face-to-face with an orb of flame, a large body inserts itself between them. The smell of singed flesh is sickening, but with a wet  _ crack _ , a body falls to the ground, flames still flickering in their hands.

Shiro turns to face him, worry in those grey eyes.  "Are you okay?"

Keith can feel his pulse hammering against his violin. He had thought the demon might cause a little chaos as demons do, before abandoning the battle to pursue his freedom…but instead, here he is, protecting him, keeping him safe. Keith doesn't know what to say.

"Do you worst, little Warlock," Sendak taunts. "I'm willing to sacrifice  _ every last pawn _ ."

Keith tears his eyes away to see Sendak's clawed hand burst forth from his body, killing intent clear. But the target isn't him. Without thinking, Keith lunges, slashing up with his bow. Sendak's eyes go wide, his right hand reaching for his bleeding throat, falling from his vantage point to the street below and going still.

It's almost comical, shielding a demon that dwarfs him entirely.

"Keith!!"

It's not so funny when he chokes on wet copper as he looks down to the claws buried in his belly. Warm, firm arms catch him gently as his knees give out, holding him close. His mother's horror-stricken face swims before him, dark spots crowding his vision.

"Lay him down," he hears her say as he closes his eyes. Heat envelopes him as his body is tenderly set upon the concrete, prickling and painful, but Keith can sense the healing magic isn't enough. 

_ So much for being a conductor of Death... _

There's a murmur of voices that Keith can barely hear, then a low voice by his ear. "Keith…make a pact with me."

His eyes fly open, landing on Shiro's face hovering above him. He's a little smaller, horns missing and skin flushed—a little more human. But those eyes are still the same, grey and kind. 

"You just," Keith chokes, chest heaving, "just got your freedom. I can't—"

"Haggar's control was no pact. I can save you. Let me bind myself to you."

Keith doesn't know if it's the words or his injuries that make his heart squeeze.

"Shiro…"

"This will only sting a moment."

There's a sharp sensation at his cheek, then warm, soft lips press to his, breathing magic into his lungs, restoring his dwindling supply. It lasts forever, and entirely too briefly when Shiro pulls back, taking the pain away with him. With his vision returned, Keith can see the fresh scar across the bridge of his nose, proof of their new bond.

"Why?..."

Never has Keith seen a demon smile so sweetly before.

"You saved me," Shiro says simply, and Keith huffs a breathless laugh.

"I guess…we saved each other."

* * *

"It's a big universe," Keith says resolutely. "This is our best chance."

"Will you be safe?" his mother asks, guilt still colouring her voice. Keith simply glances to the violin in his hand and raises an eyebrow. "Fine, fine," she sighs. "I trust you…both of you."

"We'll find each other again," Keith promises.

The portal awaits, and so his mother gives him one last kiss.

"I love you," she says as she steps through.

"I love you too, mom."

And then she's gone.

Keith takes a deep breath, bringing his violin up to rest on his collar with eyes closed. It's like muscle memory now. The bow moves in a familiar way as the strings cut his fingers and the rest cradles his face. 

A moment later, a hand presses to his opposite cheek, caressing the new scar there tenderly. Keith smiles as he opens his eyes to his demon before him. Shiro smiles back. 

"Let's find your father, Keith."

**Author's Note:**

> I was so fortunate that the wonderful [St00pz](https://Twitter.com/st00pzdraws) let me jump in on this incredible AU she concocted. Check out her art on her Twitter, including [this](https://twitter.com/st00pzdraws/status/1158062172091457542?s=19) sexy piece.
> 
> There will be a little NSFW update coming to this soon, so stay tuned 😉
> 
> You can also find me on [Twitter](https://twitter.com/copilotsheith/status/1310258433627545601?s=19)!


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